Disappearing color sunscreen compositions

ABSTRACT

Sunscreens are colored with oil-soluble dyes approved for use in skin care products (such as sunscreens, lotions, etc.). The color imparted by the dyes substantially disappears shortly after the sunscreen emulsion is applied to skin. This colored sunscreen emulsion includes a oil-soluble phase, at least one sunscreen active agent, water, and an emulsifier. The oil-soluble phase comprises from about 0.0005 to about 0.5 percent by weight of the complete emulsion of at least one oil-soluble dye. The dye imparts a color other than white to the sunscreen emulsion. 
     The sunscreen active ingredient is provided in an amount effective to protect against the actinic radiation of the sun. Sufficient water is provided to form the colored emulsion. The emulsion additionally contains at least one emulsifier in an amount effective to provide an at least substantially stable emulsion. Other optional ingredients may also be compounded into the sunscreen formulations.

This application claims the benefit of Division of Ser. No. 09/129,938filed Aug. 6, 1998, now U.S. Pat. No. 6,007,797.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION

Sunscreens are substances or compositions applied to the skin to protectthe skin from sunburn caused by the sun's ultraviolet rays. Whenuniformly applied to the body, sunscreens can be highly effective inprotecting against sunburn. However, sunscreen failure can occur whenareas of the body are missed because the sunscreen is hard to see orvisualize after being applied or rubbed onto the skin. Children are atgreater risk of sunburn than adults, since coverage on children's skintends to be more incomplete, uneven or inconsistent.

U.S. Pat. No. 5,747,011 was issued to Ross et al. and assigned toSchering-Plough HealthCare Products, Inc. This patent is herebyincorporated herein by reference in its entirety. This patent disclosesa colored, sunscreen emulsion which employs a water-soluble dye or ablend of water-soluble dyes. The color imparted by the dyes is said bythis patent to substantially disappear when the sunscreen emulsion driesafter it is spread on the skin and/or is rubbed out. The coloration inthe sunscreen is said to enable the user to more effectively protectagainst sunburn by allowing more complete and uniform coverage of thesunscreen on the skin.

The sunscreen emulsion disclosed in the Ross et al. patent includes atleast one water-soluble dye that imparts a color other than white to thesunscreen emulsion, such that when the sunscreen emulsion dries after itis spread on the skin and/or is rubbed out, the color is said tosubstantially disappear. Various water-soluble dyes are listed in thepatent as useful. The Ross et al. patent specifically discloses thatoil-soluble dyes tend to stain the skin (see col. 2, lines 39-42), andthus indicates that they should not be used in a colored sunscreen thatis intended to at least substantially lose its color upon or shortlyafter application to the skin.

BRIEF SUMMARY OF THE INVENTION

The present inventors have discovered that oil-soluble colors approvedfor use in skin care products (such as sunscreens, lotions, etc.) can beadded to the oil phase of a sunscreen to provide the disappearing colorfeature described above. This colored sunscreen emulsion comprises aoil-soluble phase, at least one sunscreen active agent, water, and anemulsifier.

The oil-soluble phase comprises from about 0.0005 to about 0.5 percentby weight of the complete emulsion of at least one oil-soluble dye. Thedye imparts a color other than white to the sunscreen emulsion, as sold.Surprisingly, when the sunscreen emulsion is spread on skin and/or isrubbed into skin, the color substantially disappears.

The sunscreen active ingredient is provided in an amount effective toprotect against the actinic radiation of the sun to a degree, as definedby its sun protection factor (SPF). Sufficient water is provided to formthe colored emulsion. The emulsion additionally contains at least oneemulsifier in an amount effective to provide an at least substantiallystable emulsion.

DETAILED DESCRIPTION OF THE INVENTION

While the invention will be described in connection with one or moreembodiments, it will be understood that the invention is not limited tothose embodiments. On the contrary, the invention includes allalternatives, modifications, and equivalents as may be included withinthe spirit and scope of the appended claims.

Oil-Soluble Dyes

The oil-soluble dyes contemplated for use in the present invention areany one or more dyes, approved now or in the future for use intopically-applied compositions, that are soluble in the water-insolublephase of a sunscreen composition in an amount effective to provide adesired color. Exemplary of these oil-soluble dyes are the following:

D&C Green #6

D&C Red #12

D&C Violet #2

D&C Yellow #11

One or more oil-soluble dyes are used in an amount effective to providea desired hue and color intensity in a sunscreen. While water-solubledyes may also be used in the present compositions, at least onewater-insoluble dye characterizes the compositions of the presentinvention. The oil-soluble dye is used as from about 0.0005 to about 0.5percent by weight, alternatively from about 0.002 to about 0.2 percentby weight, alternatively from about 0.01 to about 0.2 percent by weightof the complete emulsion. The minimum amount of dye is unlimited, thoughpreferably a perceptible color change to the composition will beprovided. The maximum amount of dye is limited to that amount whichleaves the wearer's skin an aesthetically acceptable color. Desirably,the maximum amount of dye is small enough not to leave perceptiblenon-natural coloration. Residual coloration resembling tanned human skin(i.e. sunless tanning action) may be provided, however, within the scopeof the invention.

The oil-soluble phase, sunscreen active agents, emulsifier, and othersunscreen ingredients can be materials conventionally used in sunscreencompositions and known to those skilled in the art, used in amountsconventionally used in sunscreen compositions. Examples of these andother useful ingredients can be found in U.S. Pat. No. 5,747,011(incorporated by reference above), U.S. Pat. Nos. 5,208,011 and4,522,807 (hereby incorporated herein by reference in their entireties),other patents and published references, CTFA Cosmetic IngredientDictionary, published by the Cosmetic, Toiletry and FragranceAssociation, Inc., 1110 Vermont Avenue, NW, Wash. D.C. 20005, ThirdEdition 1982, and other sources of information available to personsskilled in the art. Specific ingredients contemplated for use herein arethe following:

Sunscreen Actives

The compositions of the present invention can contain a sunscreeningeffective amount of one or more oil-soluble or water-solublesunscreening UV-B actives or a mixture of one or more UV-B actives andone or more UV-A actives. UV-A type sunscreening actives protect againstlong wavelength actinic radiation of the sun in the 320 to 400 nm rangeand UV-B type sunscreening actives protect against shorter wavelength,actinic radiation of the sun in the 290-320 nm range.

The compositions contemplated herein comprise from about 1% by weight toabout 50% by weight, preferably from about 1% to about 33% by weight, ofsunscreen-active ingredients. The present composition may desirablycontain opaque sunscreens, such as zinc oxide or titanium dioxide, whichfunction by providing an opaque barrier to UV light. The presentcomposition may desirably contain colored substances which attenuatelight, such as red petrolatum. The preferred compositions contain one ormore of the following sunscreens, which function by selectivelyabsorbing ultraviolet light having wavelengths which are responsible fortanning or burning skin.

octocrylene

2-ethylhexyl salicylate;

2-ethoxyethyl-p-methoxycinnamate;

2-ethylhexyl-p-methoxycinnamate (also known as octyl methoxycinnamate);

2-[bis(2-hydroxyethyl)-amino]ethyl salicylate;

hydroxyethylaminoethyl-p-methoxycinnamate;

pentyl 4-dimethylaminobenzoate;

octyl dimethyl p-aminobenzoic acid;

pentyl dimethyl p-aminobenzoic acid;

ethyl dihydroxypropyl p-aminobenzoic acid;

2-hydroxy-1,4-naphthoquinone;

3,3,5-trimethylcyclohexyl salicylate;

2-ethylhexyl-2-cyano-3,3-diphenyl acrylate;

ethyl 4-[bis(2-hydroxypropyl)amino]benzoate;

digalloyl trioleate;

menthyl anthranilate;

salicylic acid 3,3,5-trimethyl ester (commonly known as homomenthylsalicylate or homosalate);

glyceryl-p-aminobenzoate;

p-aminobenzoic acid;

isobutyl-p-aminobenzoate;

isoamyl-p-dimethylaminobenzoate;

2-hydroxy-4-methoxybenzophenone-5-sulfonic acid;

2-phenylbenzimidazole-5-sulfonic acid;

2-2-dihydroxy-4-methoxybenzophenone;

2-hydroxy-4-methoxybenzophenone (commonly called oxybenzone);

butylmethoxydibenzoylmethane (also known as avobenzone and sold underthe trade name PARSOL 1789);

benzophenone-8;

benzophenone-4;

benzophenone-3;

4-mono(3-hydroxypropyl)amino isomer of ethyl benzoate;

4-bis(3-hydroxypropyl)amino isomer of ethyl benzoate;

2-ethylhexyl-p-dimethylaminobenzoate;

sulfomethyl benzylidene bornanone;

urocanic acid and its esters; and mixtures thereof.

New sunscreens which may be discovered in the future may also be usedwithin the scope of the present invention.

Typical sunscreen actives include para-aminobenzoic acid up to about 15weight percent or from about 5 to 15% in admixture with other sunscreenactives; cinoxate up to about 3 weight percent or about 1 to 3% inadmixture; diethanolamine methoxycinnamate up to 10 weight percent orabout 8 to 10% in admixture; digalloyl trioleate up to 5 weight percentor about 2 to 5% in admixture; dioxybenzone up to 3 weight percent aloneor in admixture; ethyl 4-[bis(hydroxypropyl)]aminobenzoate up to 5weight percent or about 1 to 5% in admixture; glyceryl aminobenzoate upto 3 weight percent or about 2 to 3% in admixture; homosalate up to 15weight percent or about 4 to 15% in admixture; lawsone up to 0.25 weightpercent with dihydroxyacetone up to 3 weight percent, or in admixture0.25 weight percent lawsone and 3 wt. % dihydroxyacetone; menthylanthranilate up to 5 weight percent or about 3.5 to 5% in admixture;octocrylene up to 10 weight percent or 7 to about 10% in admixture;octyl methoxycinnamate up to 7.5 weight percent or about 2 to 7.5% inadmixture; octyl salicylate or 2-ethylhexyl salicylate up to 5 weightpercent or about 3 to 5% in admixture; oxybenzone up to 6 weight percentor about 2 to 6% in admixture; padimate "O" up to 8 weight percent orabout 1.4 to 8% in admixture; phenylbenzimidazole sulfonic acid up to 4weight percent or about 1 to about 4% in admixture; red veterinarypetrolatum up to 95 percent or about 30 to 95% in admixture;sulisobenzone up to 10 weight percent or about 5 to 10% in admixture;titanium dioxide up to 25 weight percent or about 2 to 25% in admixture;and triethanolamine salicylate up to 12 weight percent or about 5 to 12%in admixture.

Typical suitable UV-B type sunscreening actives include benzophenone-3,benzophenone-8, p-methoxycinnamate, substituted para-aminobenzoates,e.g.,alkyl (e.g. 2-ethylhexyl) esters of para-methoxycinnamate, octylmethoxycinnamate and octyl para-methoxycinnamate, available fromGivaudan Corp., Clifton, N.J. 07104 under the tradename Parsol MCX andusually present in the range of about 2 to 7.5 weight percent,ethylhexyl or octyl salicylate available from Harmann and Riemer,Springfield, N.J., 07081, usually in the range of about 3 to 5 weightpercent. The amount of UV-B type sunscreening active should besufficient to give an SPF of at least 2 to 15.

Typical suitable UV-A type sunscreening actives include oxybenzone,usually in the range of about 2 to about 6 weight percent. Sunscreenemulsions containing mixtures of UV-B and UV-A type sunscreen activesshould be sufficient to provide an SPF of 2 to 50.

Emulsifiers and Emulsions

A stable emulsion is a mixture of two immiscible liquids, i.e. liquidsthat are not mutually soluble, but in the presence of an emulsifier, aremechanically agitated and shaken so thoroughly together that one liquidforms drops in the other one, giving the mixture the appearance of ahomogeneous liquid. Liquids can include materials which are solid orsolid-like at room temperature, but will liquefy at a higher temperatureduring processing. The presence of an emulsifier enables one of theimmiscible liquids to remain in a continuous form, while allowing theother immiscible liquid to remain in a dispersed droplet form. Thus, onefunction of an emulsifier, a stabilizing compound, is to assist in theproduction of a stable emulsion. A secondary function of emulsifiers isto provide a thickening or "bodying" to an emulsion. Typically,emulsifiers are molecules with non-polar and polar parts that are ableto reside at the interface of the two immiscible liquids. As used hereinin reference to the water-in-oil emulsifiers, the term "HLB value" meansthe hydrophile/lipophile balance. The HLB value has been used by thoseskilled in the emulsion art for selecting emulsifiers useful forpreparing, inter alia, water-in-oil emulsions. See U.S. Pat. No.4,177,259 and references cited therein.

An "at least substantially stable emulsion" as defined herein is anemulsion which remains as one bulk phase (without visible separation tothe naked eye) for a period of at least 24 hours without any effortbeing made to redisperse its ingredients.

The sunscreen emulsions of the present invention typically comprise fromabout 35% to about 96%, preferably from about 55% to about 85%, of anaqueous phase and from about 4% to about 65%, preferably from about 15%to about 45%, of a water insoluble phase. In the present disclosure, thepercentage of any adjuvant or phase is based on the weight of the entirecomposition. The present emulsions contain the water insoluble phase andthe aqueous phase in amounts effective to provide a stable emulsionhaving activity as a sunscreen.

Some ingredients predominantly reside in the aqueous phase, otheringredients predominantly reside in the water insoluble phase, stillother ingredients reside in the interface between the phases, and someingredients are partitioned between the two phases or are found in anadditional phase of the present emulsion. Thus, an indication hereinthat an ingredient resides in a certain phase is not an exclusion ofthat ingredient from other phases of the present emulsions.

An oil-in-water (o/w) emulsion is a mixture where oil droplets (thediscontinuous phase) are dispersed in water (a continuous aqueousphase). A water-in-oil (w/o) emulsion is a mixture where water droplets(the discontinuous phase) are dispersed in oil (a continuous oil phase).Preferably the composition of the present invention is an oil-in-wateremulsion where the oil-soluble actives are dispersed in the oil phase,prior to mixture with the water phase. The type of emulsion,oil-in-water (o/w) or water-in-oil (w/o) formed, is sometimes determinedby the volume ratio of the two liquids provided the ratio issufficiently high. For example, with 5% water and 95% oil (an o/w phaseratio of 19), the emulsion likely will become w/o. For moderate ratios(<3), the type of emulsion is decided by several factors, such as orderof addition or type of emulsifier. One liquid slowly added to a secondliquid with agitation usually results in the second liquid being thecontinuous phase. Another factor is preferred solubility of theemulsifier, the phase in which the emulsifier is soluble most probablyis continuous.

More complex emulsions such as double emulsions are formed where anemulsion is dispersed in an continuous phase. For example, in an oilin-water-in oil (o/w/o) emulsion, the water in a continuous water phasecontaining dispersed oil droplets, are themselves dispersed in acontinuous oil phase. Similarly, in a water-in oil-in water (w/o/w)emulsion, the oil in a continuous phase containing dispersed waterdroplets, are themselves dispersed in a continuous water phase. Thesemore complex emulsions find use as a system for slow delivery,extraction, etc.

The sunscreen emulsions of the present invention comprise from about 35%to about 96%, preferably from about 55% to about 85%, of an aqueousphase and from about 4% to about 65%, preferably from about 15% to about45%, of a water insoluble phase. In the present disclosure, thepercentage of any adjuvant or phase is based on the weight of the entirecomposition. The present emulsions contain the water insoluble phase andthe aqueous phase in amounts effective to provide a stable emulsionhaving activity as a sunscreen.

Typical suitable emulsifiers having an HLB value about 1 to about 7include sorbitan monooleate, sorbitan sesquioleate, sorbitanisostearate, sorbitan trioleate, PEG-22/dodecyl glycol copolymer,PEG-45/dodecyl glycol copolymer, polyglyceryl-3-diisostearate,polyglycerol esters of oleic/isostearic acid, polyglyceryl-6hexaricinolate, polyglyceryl-4 oleate, polyglyceryl-4 isostearate,polyglyceryl-4 oleate/PEG-8 propylene glycol cocoate, oleamide DEA,sodium glyceryl oleate phosphate and hydrogenated vegetable glyceridesphosphate.

Other emulsifiers useful in the present invention may be non-ionic,liquid or solid at room temperature and preferably compatible, i.e.,soluble and stable with emollients. Preferred emulsifiers have a HLBvalue of less than about 5, e.g., sorbitan sequioleate (HLB value is3.7), sorbitan monooleate (HLB value is 4.3) and sorbitan trioleate (HLBvalue is 1.8). Other preferred emulsifiers include polymeric emulsifierssuch as copolymers of C10-C30 alkyl acrylates and one or more monomersof acrylic acid or methacrylic acid, also known as Pemulen Registered TMTR1 and TR2, trademark of B.F. Goodrich Inc., Cincinnati, Ohio. Otheremulsifiers include sorbitan esters such as sorbitan isostearateavailable as Crill 6, tradename of Croda Inc. of New York, N.Y.;polyglyceryl-3 distearate available as Cremophor, tradename of tradenameof BASF, Parsippany N.J.; and carbomer, which is a homopolymer ofacrylic acid crosslinked with an alkyl ether of sucrose, available asCarbopol 941, tradename of B.F. Goodrich, Cleveland, Ohio; andsurfactants such as such as DEA-cetyl phosphate, also known as AmphisolRegistered TM, trademark of Bernel Chemical Co., Englewood, N.J. Stillother emulsifiers include cetyl dimethicone copolyol, cetyl dimethylcopolyol,

During preparation of the emulsion, an acid or a base may be added toadjust the pH of one or more ingredients, e.g. to adjust the viscosityof a polymeric thickener, prior to its inclusion in the sunscreencomposition. For example, triethanolamine, a base, can be used toincrease the pH of the water phase and consequently, modify the desiredviscosity of the emulsion.

The sunscreen can have a pH of about 6.5 to about 8, preferably fromabout 6.5 to about 7.5, more preferably the pH of the sunscreen isneutral, i.e. about 7.0.

Conveniently, one or more emulsifiers can be used in the compositions ofthe present invention in amounts ranging from about 0.05 to about 20weight percent of emulsion, preferably from about 0.1 to about 15%, morepreferably from about 5 to about 10%.

Film-Forming Polymers

Water-insoluble film-forming polymers can be added to the composition toprovide a matrix or binder which physically envelops the sunscreen withthe aid of the oil-soluble solubilizer, preventing the sunscreen frombeing absorbed by the skin. The polymers also prevent the sunscreen frombeing rubbed off by physical contact with clothing, towels, furniture,other parts of the body (e.g. scratching the protected area), etc.Specific polymers contemplated for use herein include the following:

aliphatic alkenes, for example, polyethylene, oxidized polyethylene,polybutene, polypropylene, or their copolymers;

copolymers of vinyl chloride and maleic acid or anhydride;

alkyl polyvinyl pyrrolidones, such as copolymers of polyvinylpyrrolidone with eicosene or dodecene;

acrylic resins;

methacrylic resins; and

mixtures thereof.

Each said polymer can have a carbon chain length of from about 50 toabout 5000 carbon atoms.

Other polymers contemplated for use herein are those mentioned in U.S.Pat. Nos. 3,666,732 (polymers of p-aminobenzoic acid and itsderivatives, and their copolymers with acrylic, methacrylic, itaconic,or crotonic acids, alkyl esters, and hydroxyalkyl esters); 3,666,732(polyalkene resins); and 3,751,563 (polyalkene resins). The disclosuresof polymers in the U.S. patents listed in the preceding sentence arehereby incorporated herein by reference. Other water-insoluble polymerswhich have utility in skin-contacting cosmetics are also contemplatedfor use herein. The present compositions optionally contain from about1.5% to about 12.5% of one or more such polymers.

Oil-Soluble Solubilizer

The water insoluble phase of the present emulsion further optionallycomprises at least one oil-soluble solubilizer having a cohesive energybetween about 80 and about 150 calories per cc., preferably from about100 to about 115 calories per cc. The aggregate cohesive energy of allthe oil-soluble solubilizers used in a particular composition is alsopreferably from about 100 to about 115 calories per cc. The cohesiveenergy of a material is defined in Chapter 2.1 of A.F.M. Barton, CRCHandbook of Solubility Parameters and Other Cohesion Parameters, CRCPress, Inc., Boca Raton, Fla. (19183). The composition optionallycontains from about 0.1% to about 15% of such solubilizers. Oil-solublesolubilizers give the present sunscreen compositions, and particularlythe films resulting from their application, a greater affinity for skin.Oil-soluble solubilizers also function as plasticizers for the polymervehicles described above, so the film of the sunscreen composition willbe mobile enough to form a thin layer on the wearer's skin and flexibleenough to conform closely to the wearer's skin during use.

Specific oil-soluble solubilizers contemplated herein include thefollowing:

aliphatic lactates of fatty acids having from about 12 to 20 carbonatoms, for example, myristyl lactate;

Guerbet alcohols;

fatty alcohols having from 6 to 22 carbon atoms, such as stearyl alcoholor a mixture of fatty alcohols;

dialkyl maleates;

alkyl ricinoleates;

alkyl hydroxystearates;

alkyl acetyl ricinoleates;

nonionic surfactants having HLB's between 1 and about 5;

alkyl salicylates such as octyl salicylate;

and mixtures thereof.

("Alkyl" is defined herein generally to include straight or branchedchain alkyl having from 1 to about 22 carbon atoms.) Exemplary nonionicsurfactants useful herein include lanolin alcohols, glycerol monooleate,and sorbitan esters of fatty acids (such as sorbitan stearate andsorbitan oleate).

Another optional ingredient of the water insoluble phase is from about0.1 to about 10% by weight of alkoxylated castor oil, more broadlydefined as consisting essentially of alkoxylated ricinolein. From 1 to100 moles of an alkylene oxide (preferably ethylene oxide), preferablyfrom about 5 to about 40 moles of ethylene oxide, may be combined witheach molecule of ricinolein. Mixtures of alkoxylated castor oils havingdifferent amounts or kinds of alkylene oxide content are alsocontemplated for use herein.

Water-Insoluble Antioxidants

Antioxidants such as tocopherol may be used in the water insoluble phase

Water

Water is employed in amounts effective to form the emulsion. Forhydrophilic or water-loving ingredients, e.g., emulsifiers, emolients,etc., the amount of water should be sufficient to at least solubilizethese ingredients. For hydrophobic or water-repelling ingredients, thewater should be employed in amounts to serve as the continuous phase ofthe emulsion, at least for oil-in water emulsions. Thus, amount of waterin the emulsion or composition can range from about 2 to 95 weight %,preferably from 50 to 85%. Deionized water may optionally be used.

Emollients

An emollient is an oleaginous or oily substance which helps to smoothand soften the skin, and may also reduce its roughness, cracking orirritation. Typical suitable emollients include mineral, oil, having aviscosity in the range of 50 to 500 centipoise (cps), lanolin oil,coconut oil, cocoa butter, olive oil, almond oil, macadamia nut oil,aloe extracts such as aloe vera lipoquinone, aloe vera gel, syntheticjojoba oils, natural sonora jojoba oils, safflower oil, corn oil, liquidlanolin, cottonseed oil and peanut oil.

Other suitable emollients and adjuvants include squalane, castor oil,polybutene, odorless mineral spirits, sweet almond oil, avocado oil,calophyllum oil, ricin oil, vitamin E acetate, olive oil, silicone oilssuch as dimethylpolysiloxane and cyclomethicone, linolenic alcohol,oleyl alcohol, the oil of cereal germs such as the oil of wheat germ,isopropyl palmitate, octyl palmitate which is commercially available asLexol EHP, tradename of Inolex Co. of Philadelphia, Pa., caprictriglyceride, caprylic triglyceride, isopropyl myristate, hexadecylstearate, butyl stearate, decyl oleate, acetyl glycerides, theoctanoates and benzoates of (C₁₂ -C₁₅) alcohols, the octanoates anddecanoates of alcohols and polyalcohols such as those of glycol andglycerol, ricin oleates of alcohols and poly alcohols such as those ofisopropyl adipate, hexyl laurate and octyl dodecanoate.

Other suitable emollients which are solids or semi-solids at ambienttemperatures may be use in amounts sufficient to provide liquid topicalcompositions. Such solid or semi-solid cosmetic emollients includehydrogenated lanolin, hydroxylated lanolin, acetylated lanolin,petrolatum, isopropyl lanolate, butyl myristate, cetyl myristate,myristyl myristate, myristyl lactate, cetyl alcohol, isostearyl alcoholand isocetyl lanolate. One or more emollients can optionally be includedin the sunscreen emulsion in an amount ranging from about 10 to about 50weight %, preferably about 20 to about 40%.

Humectants

A humectant is a moistening agent that promotes retention of water dueto its hygroscopic properties. Suitable humectants include glycerin,polymeric glycols such as poyethylene glycol and polypropylene glycol,and sorbitols such as sorbitol solution. One or more humectants canoptionally be included in the in the sunscreen in amounts from about 1to 10 weight %.

Dry-Feel Modifier

A dry-feel modifier is an agent which when added to a emulsion, impartsa "dry feel" to the skin when the emulsion dries. Dry-feel modifiers mayalso reduce sunscreen migration on the skin. Dry feel modifiers caninclude starches, talc, kaolin, chalk, zinc oxide, silicone fluids,inorganic salts such as barium sulfate and sodium chloride, C₆ to C₁₂alcohols such as octanol; sulfonated oils; surface treated silica,precipitated silica, fumed silica such as Aerosil Registered TMavailable from the Degussa Inc. of New York, N.Y. or mixtures thereof;dimethicone, a mixture of mixture of methylated linear siloxanepolymers, available as DC200 fluid, tradename of Dow Corning, Midland,Mich. One or more dry-feel modifiers can optionally be included in thesunscreen in amounts ranging from 0.01 to about 20 weight %, preferablyfrom about 0.5 to about 6 weight %.

Waterproofing Agents

A waterproofing agent is a hydrophobic material that imparts filmforming and waterproofing characteristics to an emulsion. Typicalsuitable waterproofing agents include copolymers derived frompolymerization of octadecene-1 and maleic anhydride in accordance withthe published procedures such as those in U.S. Pat. No. 3,860,700 andReissue No. 28,475. A preferred waterproofing agent is a polyanhydrideresin, also known as PA-18, tradename of the Chevron Chemicals Co., SanFrancisco, Calif. Another preferred waterproofing agent is a copolymerof vinyl pyrollidone and eicosene monomers such as Ganex Polymer,tradename of ISP Inc. of Wayne, N.J. Another suitable waterproofingagent is dimethicone.

By the term "waterproofing effective amount of at least onewaterproofing agent" means the waterproofing agent(s) is used in amountseffective to allow the sunscreen to remain on the skin after exposure tocirculating water for at least 80 minutes using the procedures describedin "Sunscreen Drug Products for OTC Human Use", Federal Register, Vol.43, Aug. 25, 1978, Part 2, pp 38206-38269. One or more waterproofingagents can optionally be included in the sunscreen composition in anamount ranging from about 0.01 to about 10.0 weight percent, preferablyabout 1.0 to about 10.0 percent.

Antimicrobial Preservative

An antimicrobial preservative is a substance or preparation whichdestroys, prevents or inhibits the multiplication/growth ofmicroorganisms in the sunscreen composition and may offer protectionfrom oxidation. Preservatives are used to make self-sterilizing, aqueousbased products such as emulsions. This is done to prevent thedevelopment of microorganisms that may be in the product from growingduring manufacturing and distribution of the product and during use byconsumers who may inadvertently contaminate the products during normaluse. Typical preservatives include the lower alkyl esters ofpara-hydroxybenzoates (parabens) especially, methylparaben,propylparaben, isobutylparaben and mixtures thereof, benzyl alcohol andbenzoic acid, or imidazolidinyl urea. One or more antimicrobialpreservatives can optionally be included in the sunscreen composition inan amount ranging from about 0.001 to about 10 weight percent,preferably about 0.05 to about 2 percent.

Antioxidants

An antioxidant is a natural or synthetic substance added to thesunscreen to protect from or delay its deterioration due to the actionof oxygen in the air (oxidation). Anti-oxidants prevent oxidativedeterioration which may lead to the generation of rancidity andnonenyzymatic browning reaction products. Typical suitable antioxidantsinclude propyl, octyl and dodecyl esters of gallic acid, butylatedhydroxyanisole (BHA)(usually as a mixture of ortho and meta isomers),butylated hydroxytoluene (BHT), nordihydroguaiaretic acid, vitamin E,vitamin E acetate, vitamin C and alkylated parabens such asmethylparaben and propylparaben. One or more antioxidants can optionallybe included in the sunscreen composition in an amount ranging from about0.001 to about 5 weight percent, preferably about 0.05 to about 2percent.

Chelating Agents

Chelating agents are substances used to chelate or bind metallic ionswith a certain heterocylic ring structure so that the ion is held bychemical bonds from each of the participating ring. Suitable chelatingagents include ethylene diaminetetraacetic acid (EDTA), EDTA disodium,calcium disodium edetate, EDTA trisodium, EDTA tetrasodium and EDTAdipotassium. One or more chelating agents can optionally be included inthe sunscreen in amounts ranging from about 0.001 to about 0.1 weightpercent.

Other Adjuvants

Some other adjuvants which may be employed are counterirritants such asallantoin, plant extracts such as chamomile extract, vitamins such asVitamin E, Vitamin K1, Vitamin A, Vitamin B's, Vitamin C, etc.,electrolytes such as sodium chloride, fatty acids such as stearic acid,etc.

Fragrances

Fragrances are aromatic compounds which can impart an aestheticallypleasing aroma to the sunscreen composition. Typical fragrances includearomatic materials extracted from botanical sources (i.e. rose petals,gardenia blossoms, jasmine flowers, etc.) which can be used alone or inany combination to create essential oils. Alternatively, alcoholicextracts may be prepared for compounding fragrances. One or morefragrances can optionally be included in the sunscreen composition in anamount ranging from about 0.001 to about 10 weight percent, preferablyabout 0.05 to about 5 percent.

Leveling Agents

The emulsion can contain leveling agents, which are ingredientsdispersed in the emulsion to assist the application of a uniform film ofthe composition on the skin. From 0 to about 5%, preferably from 0 toabout 3.5%, of the composition may be a leveling, agent. Exemplaryleveling, agents are silica, clays or earths, titanium dioxide, mica,and zinc oxide. The leveling agent can also be added in larger amountsto function as an opaque barrier layer.

Propellants

Propellants may be blended into the composition to facilitate deliveryof the sunscreen in aerosol form, using conventional aerosol technology.

Miscellaneous Ingredients

Although an attempt has been made to give many examples of suitableingredients, the foregoing listing is not exhaustive. The incorporationof any listed or unlisted ingredients in any amount, great or small,which does not destroy the utility of the composition as a sunscreen isexpressly contemplated herein.

Dispensers

The sunscreen emulsions of the present invention containing thedisappearing color indicator can be stored or dispensed in any containersuitable for convenient delivery, i.e. pouring or spraying. Suchcontainers can include but are not limited to tubes, jars, bottles,lotion pumps, pump spray bottles and aerosols.

WORKING EXAMPLES

The following working examples are provided for specific guidance on howto make and use the present compositions. The provision of specificexamples in no way limits the full scope of the invention as presentlydisclosed and claimed. The inventors contemplate that the presentinvention can be carried out using a variety of different sunscreencompositions, by adding a suitable quantity of an oil-soluble dye to thecomposition.

Example 1

A water-in-oil sunscreen emulsion composition is made as follows. Anemulsifier or water-insoluble phase is prepared by blending, at roomtemperature, cetyl dimethicone copolyol, polyglyceryl-3-distearate,polyglyceryl-4 isostearate, cetyl dimethyl copolyol, hexyl laurate,caprylic and/or capric triglyceride, propylparaben, methylparaben,p-methoxycinnamate, ethylhexyl salicylate, oxybenzone, minoringredients, and about 0.12% by emulsion weight of a color blend of D&CGreen #6, D&C Red #12, and D&C Violet #2 in suitable proportions to makea purple emulsion.

Separately, an aqueous phase is prepared by combining, at roomtemperature, deionized water, aloe vera gel, sodium chloride, chamomileextract, ascorbic acid (Vitamin C), and minor ingredients.

The two phases are then combined by adding the water phase to theemulsifier phase with constant mixing. The mixture is then homogenizedwith a suitable homogenizing mill until the required viscosity isreached.

The resulting sunscreen is applied to human skin and rubbed in well, assunscreens are conventionally applied. The sunscreen is initiallypurple. As it is rubbed in the color fades, then essentially disappears,leaving the treated skin a normal skin color.

Example 2

Example 1 is repeated, but substituting for the color blend of thatexample a color blend of D&C Green #6 and D&C Yellow #11 in proportionssuitable to make a green emulsion. Use of the emulsion as a sunscreen isdemonstrated, with essentially the same result.

Example 3

Sea & Ski Kids Color Sun Block (SPF 30) is modified by adding to it thecolor blend of Example 1. Use of the emulsion as a sunscreen isdemonstrated, with essentially the same result.

What is claimed is:
 1. A colored sunscreen composition for application to human skin, comprising:a sunscreen active to protect the skin from ultraviolet radiation; an oil-soluble dye to impart a color, other than white, to the composition; and water, wherein application of the composition to the skin imparts the color to the skin and wherein the color substantially disappears when the composition is rubbed and/or spread onto the skin.
 2. A composition according to claim 1, wherein the dye comprises one of the following:D&C Green $6, D&C Red #12, D&C Violet #2, D&C Yellow #11, and mixtures thereof.
 3. A composition according to claim 1, wherein the dye comprises about 0.0005 to about 0.5 percent by weight of the composition.
 4. A composition according to claim 1, wherein the dye comprises about 0.002 to about 0.2 percent by weight of the composition.
 5. A composition according to claim 1, wherein the sunscreen active comprises UV-A active, UV-B active, and mixtures thereof.
 6. A composition according to claim 1, wherein the active comprises between about 1% to 50% by weight of the composition.
 7. A composition according to claim 6, wherein the active comprises between about 1% to 33% by weight of the composition.
 8. A composition according to claim 1, wherein the active comprises one of zinc oxide or titanium dioxide.
 9. A composition according to claim 1, further comprising an emulsifier to provide a the composition with a substantially stable emulsion.
 10. A composition according to claim 9, wherein the emulsifier comprises an oil-in-water emulsifier.
 11. A composition according to claim 9, wherein the emulsifier comprises an water-in-oil emulsifier.
 12. A composition according to claim 1, further comprising a film-forming polymer.
 13. A composition according to claim 1, further comprising an oil-soluble solubilizer.
 14. A composition according to claim 1, further comprising a water-insoluble antioxidant.
 15. A composition according to claim 1, further comprising an emollient.
 16. A composition according to claim 1, further comprising a humectant.
 17. A composition according to claim 1, further comprising a dry-feel modifier.
 18. A composition according to claim 1, further comprising a waterproofing agent.
 19. A composition according to claim 1, further comprising an antimicrobial preservative.
 20. A composition according to claim 1, further comprising an antioxidant.
 21. A composition according to claim 1, further comprising a cheating agent.
 22. A composition according to claim 1, further comprising one or more of an adjuvant, a propellant, a leveling agent, and a dispenser.
 23. A composition according to claim 1, further comprising a fragrance.
 24. A method of forming a colored sunscreen composition, comprising the steps of:mixing a sunscreen active with water and an oil-soluble dye to impart a color, other than white, to the composition, wherein application of the composition to the skin imparts the color to the skin and wherein the color substantially disappears when the composition is rubbed and/or spread onto the skin.
 25. A colored composition for application to human skin, comprising:an oil-soluble dye to impart a color, other than white, to the composition; and water, wherein application of the composition to the skin imparts the color to the skin and wherein the color substantially disappears when the composition is rubbed and/or spread onto the skin. 